The Effect of Visible Light Irradiation on Positronium Formation in Polyethylene at Low Temperature |
| Y. Itoa, T. Hiradeb, E. Hamadac, T. Suzukid and Y. Itoe a High Energy Accelerator Research Organization (KEK), Tanasi-Branch, 3-2-1 Midori, Tanasi-si, Tokyo 188-8501, Japan b Department of Materials Science, Japan Atomic Energy Research Institute, Tokai, Naka, Ibaraki 319-1106, Japan c The Graduate University for Advanced Studies, High Energy Accelerator Research Organization (KEK), 1-1, Oho, Tsukuba, Ibaraki 305-0801, Japan d High Energy Accelerator Research Organization (KEK), 1-1, Oho, Tsukuba, Ibaraki 305-0801, Japan e Research Center for Nuclear Science and Technology, University of Tokyo, Tokai, Naka, Ibaraki 319-1106, Japan |
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| The effect of visible light exposing on the ortho-positronium formation in polyethylene was studied. Lifetime spectra of positrons in polyethylene were measured in the temperature range between 50 K and 370 K. It was observed that the visible light quenches the enhancement of ortho-positronium intensity (I3) at lower temperature than ca. 250 K - the glass transition temperature of polyethylene. On the other hand, the lifetime of ortho-positronium component (τ3) was not affected by the presence of the visible light. |
| DOI: 10.12693/APhysPolA.95.533 PACS numbers: 78.70.Bj |